hashcat

Hashcat is an open-source password recovery tool designed to recover or audit password hashes by performing offline attacks. It supports a broad range of hash types used by operating systems, applications, and network protocols. It is widely used in security testing, password auditing, and incident response to verify password strength and recover access to forgotten credentials.

Implementation and capabilities: Hashcat is a cross-platform command-line program, released under the MIT license and maintained by the Hashcat project. It is written in C and uses high-performance computing capabilities through GPU-accelerated kernels via OpenCL and CUDA, enabling large-scale candidate generation for many hash types. While best performance comes from GPUs, it can also run on CPUs.

Attack modes and features: It provides multiple attack modes, including dictionary-based, brute-force, and combinatorial attacks, along with rule-based and hybrid approaches that combine wordlists with masks or other transformations. It supports custom rule sets, mask generation, and performance benchmarking to compare devices and hash types. It also negotiates multi-GPU and distributed cracking setups.

Hash coverage and ecosystem: Hashcat supports thousands of hash types, including common cryptographic hashes (MD5, SHA-1, NTLM), password-based key derivation functions (PBKDF2, bcrypt, scrypt), and message authentication codes. It is commonly used for security assessments, password recovery in legitimate contexts, and research into password hygiene.

Legal and ethical considerations: The use of hashcat for cracking passwords without authorization is illegal in many jurisdictions. Responsible use requires explicit permission from system owners and adherence to applicable laws and policies.